chapter 20: digestive system

Chapter 20: Digestive System

Chapter 21: Urinary System

Functions of Digestion Ingest food Break down food in to small

molecules: Mechanical digestion- Chemical digestion –

Absorption Elimination

Carbohydrates Include sugars and their polymers Monomer is the monosaccharide Include 3 – 7 carbons with the –OH

group being present on each carbon except one, which is double bonded to an oxygen (carbonyl group)

Lipids A group of polymers that have

one characteristic in common, they do not mix with water. They are hydrophobic.

Some important groups are fats, phospholipids, and steroids.

Enzymes Increase speed of

chemical reactions - catalyst

A protein Can change

shape if conditions are not favorable.

Alimentary Canal Hollow tube that begins at the mouth,

ends at the anus Mouth Pharynx Esophagus Stomach Small intestine Large intestine Rectum

A. Mouth Forms a bolus Chemical digestion

– mucous, amylase (break down carbs)

Mechanical digestion: chewing

• Roof of mouth: Hard palate Soft palate

Tongue and Taste Lingual frendulum

– attaches tongue to floor of mouth

Taste buds: Papillae:

elevations on tongue

Salivary Glands Saliva – water

mucous, amalase Parotid – front of

and below ears. (mumps)

Sublingual submandibular

B.Pharynx Region between mouth and

esophagus “throat” Function – swallowing Epiglottis – blocks larynx Uvula – back of throat

C. Esophagus3. Lined by mucous

membrane and smooth muscle

4. Peristalsis – involuntary contraction of esophagus

5. Heartburn – (acid reflux)

Esophagus Continued

D. Stomach Stores food and

digests protein Rugae – folds

inside stomach Ulcers

Stomach Continued Gastric Juice –

produces Chyme Pepsin – enzyme that

digests protein HCL – kills bacteria,

breaks down food, Intrinsic factor –

absorption of B12. Mucous – softens food Gastrin – hormone

that causes gastric juice to be released.

E. Small Intestine Function- receives secretions from

the liver, pancreas and absorption of nutrients.

Lined with Villi – furry looking, absorption, increase surface area

F. Large Intestine Function – absorb

water, produce feces

E.coli bacteria present                                                               

Disorders of Large Intestine

Diarrhea – Constipation – Appendicitis – Diverticuloisis – colon cancer

Colonoscopy

Part 2: Digestive System

Accessory organs – food does not pass through

1. Pancreas Secretes Sodium Bicarbonate and

enzymes to digest carbohydrates, proteins, and fats

2. Liver – Largest gland Storage of glucose as

glycogen Destruction of old red

blood cells – this creates bilirubin

Production of bile Plasma proteins Detoxification of blood Storage of iron and

other vitamins

Liver Lobule Anatomy Functional unit of

the liver. Blood travels from

small intestine – hepatic portal vein – to various liver lobules.

3. Liver Disorders Hepatitis – inflammation of the

liver due to contaminated drinking water, sexual transmission, or blood transfusion

Cirrhosis of liver Cirrhosis – chronic

disease due to excessive amount of alcohol. Liver becomes fatty tissue.

Jaundice Jaundice –

yellowish tint due to large amounts of bilirubin in blood.

C. Gallbladder Storage of bile – emulsifies fats

and neutralize acids

Chapter 21

Excretory system

Structures of Urinary System

1. 2 kidneys 2. 2 ureters –

tube that leads to bladder

3. Bladder – stores urine

4. Urethra – tube for eliminating urine

Structure of Kidney Renal cortex –

outer layer, filtration Renal medulla –

middle layer, filtration, absorption

Renal pelvis – urine collection and transport

Renal artery - Renal vein -

Functions of Kidney

I.                

Kidney Function – filter blood that has collected wastes from cells.

A.   Excrete waste – urea, uric acid, creatine, ammonium

B.  Maintain blood volume – regulating water excretion

C.   monitor electrolytes in blood D.   monitor blood pH E.   secrete Renin – enzyme to help

maintain blood pressure F.   stimulates red blood cell production

Lipids A group of polymers that have

one characteristic in common, they do not mix with water. They are hydrophobic.

Some important groups are fats, phospholipids, and steroids.